#include <REGX52.H>
void Delay(unsigned int xms)		//@12.000MHz
{
	unsigned char i, j;
	while(xms)
		{
				i = 2;
				j = 239;
				do
				{
						while (--j);
				} while (--i);
				xms--;
		}
}

void mian()
{
while(1)
	{
		if(P3_1==0)
		{
			Delay(20);
			while(P3_1==0);
			Delay(20);
			
			P2_0=~P2_0;
		}

	}
}